The words, |The head of every man is Christ...and the head of Christ is God| misused by the Arians, are now turned back against them, to their confutation. Next, another passage of Scripture, commonly taken by the same heretics as a ground of objection, is called in to show that God is the Head of Christ, in so far as Christ is human, in regard of His Manhood, and the unwisdom of their opposition upon the text, |He who planteth and He who watereth are one,| is displayed. After which explanations, the meaning of the doctrine that the Father is in the Son, and the Son in the Father, and that the faithful are in Both, is expounded.
28. Now let us examine some other objections raised by the Arians. It is written, say they, that |the head of every man is Christ, and the head of woman is man, and the head of Christ is God.| Let them, if they please, tell me what they mean by this objection -- whether to join together, or to dissociate, these four terms. Suppose they mean to join them, and say that God is the Head of Christ in the same sense and manner as man is the head of woman. Mark what a conclusion they fall into. For if this comparison proceeds on the supposed equality of the terms of it, and these four -- woman, man, Christ, and God -- are viewed together as in virtue of a likeness resulting from their being of one and the same nature, then woman and God will begin to come under one definition.
29. But if this conclusion be not satisfactory, by reason of its impiety, let them divide, on what principle they will. Thus, if they will have it that Christ stands to God the Father in the same relation as woman to man, then surely they pronounce Christ and God to be of one substance, inasmuch as woman and man are of one nature in respect of the flesh, for their difference is in respect of sex. But, seeing that there is no difference of sex between Christ and His Father, they will acknowledge then that which is one, and common to the Son and the Father, in respect of nature, whereas they will deny the difference lying in sex.
30. Does this conclusion content them? Or will they have woman, man, and Christ to be of one substance, and distinguish the Father from them? Will this, then, serve their turn? Suppose that it will, then observe what they are brought to. They must either confess themselves not merely Arians, but very Photinians, because they acknowledge only the Manhood of Christ, Whom they judge fit only to be placed on the same scale with human beings. Or else they must, however contrary to their leanings, subscribe to our belief, by which we dutifully and in godly fashion maintain that which they have come at by an impious course of thought, that Christ is indeed, after His divine generation, the power of God, whilst after His putting on of the flesh, He is of one substance with all men in regard of His flesh, excepting indeed the proper glory of His Incarnation, because He took upon Himself the reality, not a phantom likeness, of flesh.
31. Let God, then, be the Head of Christ, with regard to the conditions of Manhood. Observe that the Scripture says not that the Father is the Head of Christ; but that God is the Head of Christ, because the Godhead, as the creating power, is the Head of the being created. And well said [the Apostle] |the Head of Christ is God;| to bring before our thoughts both the Godhead of Christ and His flesh, implying, that is to say, the Incarnation in the mention of the name of Christ, and, in that of the name of God, oneness of Godhead and grandeur of sovereignty.
32. But the saying, that in respect of the Incarnation God is the Head of Christ, leads on to the principle that Christ, as Incarnate, is the Head of man, as the Apostle has clearly expressed in another passage, where he says: |Since man is the head of woman, even as Christ is the Head of the Church;| whilst in the words following he has added: |Who gave Himself for her.| After His Incarnation, then, is Christ the head of man, for His self-surrender issued from His Incarnation.
33. The Head of Christ, then, is God, in so far as His form of a servant, that is, of man, not of God, is considered. But it is nothing against the Son of God, if, in accordance with the reality of His flesh, He is like unto men, whilst in regard of His Godhead He is one with the Father, for by this account of Him we do not take aught from His sovereignty, but attribute compassion to Him.
34. But who can with a good conscience deny the one Godhead of the Father and the Son, when our Lord, to complete His teaching for His disciples, said: |That they may be one, even as we also are one.| The record stands for witness to the Faith, though Arians turn it aside to suit their heresy; for, inasmuch as they cannot deny the Unity so often spoken of, they endeavour to diminish it, in order that the Unity of Godhead subsisting between the Father and the Son may seem to be such as is unity of devotion and faith amongst men, though even amongst men themselves community of nature makes unity thereof.
35. Thus with abundant clearness we disprove the objection commonly raised by Arians, in order to loosen the Divine Unity, on the ground that it is written: |But he who planteth and he who watereth are one.| This passage the Arians, if they were wise, would not quote against us; for how can they deny that the Father and the Son are One, if Paul and Apollos are one, both in nature and in faith? At the same time, we do grant that these cannot be one throughout, in all relations, because things human cannot bear comparison with things divine.
36. No separation, then, is to be made of the Word from God the Father, no separation in power, no separation in wisdom, by reason of the Unity of the Divine Substance. Again, God the Father is in the Son, as we ofttimes find it written, yet [He dwells in the Son] not as sanctifying one who lacks sanctification, nor as filling a void, for the power of God knows no void. Nor, again, is the power of the one increased by the power of the other, for there are not two powers, but one Power; nor does Godhead entertain Godhead, for there are not two Godheads, but one Godhead. We, contrariwise, shall be One in Christ through Power received [from another] and dwelling in us.
37. The letter [of the unity] is common, but the Substance of God and the substance of man are different. We shall be, the Father and the Son [already] are, one; we shall be one by grace, the Son is so by substance. Again, unity by conjunction is one thing, unity by nature another. Finally, observe what it is that Scripture hath already recorded: |That they may all be one, as Thou, Father, art in Me, and I in Thee.|
38. Mark now that He said not |Thou in us, and we in Thee,| but |Thou in Me, and I in Thee,| to place Himself apart from His creatures. Further He added: |that they also may be in Us,| in order to separate here His dignity and His Father's from us, that our union in the Father and the Son may appear the issue, not of nature, but of grace, whilst with regard to the unity of the Father and the Son it may be believed that the Son has not received this by grace, but possesses by natural right of His Sonship.